Shortening the design cycle and improving design quality is one of the keys to shortening the entire mold development cycle. The modular design is to use the similarity in structure and function of the product components to achieve standardization and combination of products. A large number of practices have shown that modular design can effectively reduce product design time and improve design quality. Therefore, this paper explores the use of modular design methods in mold design.
1. Create a module library
The module library is built in three steps: module partitioning, constructing feature models, and generating user-defined features. Standard parts are special cases of modules and exist in the module library. The definition of a standard part requires only the last two steps. Module partitioning is the first step in modular design. Whether the module division is reasonable or not directly affects the function, performance and cost of the modular system. The module division of each type of product must undergo technical investigation and repeated argumentation to obtain the division result.
For molds, functional modules and structural modules are mutually tolerant. The structural module can have a large structural change in a local range, so that it can contain functional modules; and the functional structure of the functional module may be relatively fixed, so that it can contain structural modules. After the module design is completed, the feature model of the required module is manually constructed in the Pro/E Part/Assembly space, and the user-defined feature function of Pro/E is used to define two variable parameters of the module: Variable size and assembly relationships form User-Defined Features (UDFs). Generate a user-defined feature file (a file with a suffix of gph) and store it by grouping technology, that is, complete the creation of the module library.
2. Module library management system development
The system realizes the module determination through two inferences, structure selection reasoning and automatic modeling of the module. The first reasoning gives the general structure of the module, and the second reasoning finally determines all the parameters of the module. In this way, the module "plasticity" goal is achieved. In the structure selection reasoning, the system accepts the module name, function parameters and structural parameters input by the user, performs inference, and obtains the name of the applicable module in the module library.
If the result is not satisfactory, the user can specify the module name. The module obtained in this step is still uncertain, and it lacks definitions of dimensional parameters, precision, material characteristics, and assembly relationships. In the automatic modeling reasoning, the system uses the input size parameters, precision features, material features and assembly relationship definitions to drive the user-defined feature model, dynamically and automatically construct the module feature model and automatically assemble.
The automatic modeling function was developed using Pro/TOOLKIT, a secondary development tool for C and Pro/E. The mold design can be quickly completed through the call of the module, and the mold design cycle is significantly shortened after the application of the system. Since the quality of the module is carefully considered in the design of the module, the quality of the mold is guaranteed. The module library stores mutually independent UDFs, so the system is extensible.